From Huffington Post: Navratri, Durga Puja: Worshipping The Divine Mother
Navratri is observed in the Hindu calendar month of Ashwin. In 2012, Navratri is observed from Oct. 16 until Oct. 24. Durga Puja celebrations began on Oct. 20, 2012.
Navratri is the Hindu festival of nine nights dedicated to the glorification of Shakti, the feminine form of the Divine. During these nine nights, the mother goddess is worshipped in nine different forms. Navratri culminates on the 10th day with the festivities of Vijayadashami. A common greeting during this festival is Shubh Navratri (Happy Navratri).
Navratri is celebrated all over India and among the Hindu diaspora with great fanfare. Prior to the festival, skilled artisans prepare clay models of the goddess in her various manifestations. Many Hindus take part in special ceremonies, rituals, fasts and festivities. People buy new clothes, prepare delicious sweets and buy gifts for family and friends. During Navratri, many Hindus in Gujarat and elsewhere wear colorful costumes and perform a special type of vigorous dance known as garba. Traditionally, garbas are performed around an earthen lamp or images / statues of the mother goddess.